Steganography Tool (Hide Text in Image)
Hide a text message inside a PNG image, invisible to the eye, or extract a message someone's hidden for you.
About this tool
Uses least-significant-bit (LSB) steganography — each hidden bit replaces the lowest, least visually significant bit of a pixel's red/green/blue value, which is far too subtle a change for the eye to notice but easy for software to read back out. Only works reliably with lossless formats: the downloaded file is always a PNG, and re-saving or converting it to JPEG afterwards will destroy the hidden message.
Any image you can open works as the starting picture, including a JPEG photo, and the tool tells you how much text it can hold: roughly three bits per pixel, so a typical phone photo has room for a whole book. Fully transparent and semi-transparent pixels are skipped, because browsers change their colours slightly when reading them. The message is hidden, not encrypted: anyone who uses a tool like this one can read it. For a secret message, encrypt it first with the AES Encrypt/Decrypt tool and hide the encrypted text. Everything happens in your browser; your image is never uploaded.